As we all know, currently it is very common to employ containers to carry or transport various types of materials, and these containers are of a series of specifications from the big to the small. In the purposes of convenience quickness of production turnover or transportation, and savings of costs, plastic containers become widespread. Such containers mostly have a bottom and integrated or foldable four side plates. When the volume of the container is too large, a door that can be opened is usually provided at one or more side plates for easy access to items at the bottom of the container or for installation or disassembly of some additional components at the bottom of the container. Typically, the door that can be opened flushes with the side plate, and has a locking mechanism ensuring that it would not be accidentally opened. When it is needed to open the door, after being unlocked, the door is flipped outwardly by approximately 180 degrees and then is lean against the side plate substantially, so as to reduce the space it occupies, and makes it more convenient for people to operate through an opening of the side plate.
Chinese patent application No. 201210031893.7 shows a novel method for connecting the door and the side plate, the entire disclosure of which is incorporated herein by reference. As shown in FIG. 1, it uses a generally U-shaped hinge body, which is provide with at least two groups of hinge pins, respectively connected with the upper and lower hinge bases, wherein the upper hinge base is connected with the door and the lower hinge base is connected with the side plate. The upper and lower hinge base may both be rotated by 90 degrees around the hinge pins of the hinge body, in this way, the door could be flipped outwardly relative to the side plate by 180 degrees. More advantageously, the hinge body, the upper and lower hinge bases could be arranged within the thickness between the internal and external surfaces of the side plate. When the door is closed, the hinge is substantially invisible from the appearance of the container.
Although the hidden hinge described above can greatly improve the overall product appearance, however, since there are hinge mounting holes provided at the hinge mounting parts of the side plate and the door, and the hinge mounting holes and the hinge positioning structures will still be seen from the appearance of the container after the hinge is installed. Further, since the hinge mounting holes are provided on the side plate and the door, and therefore, the strength of the hinge mounting parts on the side plate and the door is also affected to some extent.